This project involves computer-based mathematical analysis, pattern recognition, and image processing in support of diagnostic activities in the Diagnostic Imaging Department of the Clinical Center and collaborating Institutes. Applications include computerized ECG-gated radionuclide angiocardiography and scintigraphic studies of regional cerebral blood flow, renal dynamics, gastric fluid dynamics, and pulmonary ventilation-perfusion relationships as well as computer analysis of ultrasonograms.